1. Field of the Invention
The present invention is directed to an optical assembly and more particularly to an improved focusing mechanism and method of assembly for binoculars.
2. Description of the Prior Art
As with most commercial optical systems a number of subtle design considerations are involved in providing a cost competitive and esthetically pleasing product for the consumer.
Any spectator at a sports event or observer viewing an activity at a substantial distance will generally resort to binoculars. In this regard, a binocular design must take into consideration the physiological effects on the user plus the esthetic appearance and functionability of the binoculars. If the binocular is not in good balance it can become tiring on the User. For example, if the binocular assembly extends too far from the head of the observer, the cantilevered extension will magnify any vibrations that are introduced. Conversely, if the binocular mechanism is too heavy, then it will introduce fatigue and cause muscle spasms preventing an extended use period. It is also important not to design the binocular mechanism to be too light because this in itself will permit the human anatomy to cause or at least introduce vibrations in the system and will also render the equipment prone to physical damage. Finally, since the binoculars are frequently utilized in spectator sports, a highly esthetic appearance is appealing to the user and accordingly enhances its saleability.
Generally binoculars will include a standard objective lens system, at least one or more prisms for folding the optical axis, a focusing lens and finally an ocular lens. This optical system is provided for each eye. Generally the focusing lens in both the left and right optical system will be moved in unison by the rotation of a knarled knob which interacts with a threaded shaft carrying the respective focusing lenses. While the knob provides adequate focusing, it also adds bulk to the binocular housing and does not adapt itself to a split housing with relative movement.
It is still a goal of the prior art to provide a lightweight compact easily manufactured binocular mechanism that is highly attractive in its appearance and functionable for the consumer.